Your first task was to
determine the density of
the cell suspension using a haemocytometer (left). The answer was
~2 x 106 for those that took the practical on 8th Jan
'03, and ~3x 106 for the remaining students who had the
practical on the 15th Jan '03.

Cell Dilution

The cell density was measured at 2 x 106/ml

(or 3 x 10615thJaní03
)

The experiment required a density of 1.5 x 106/ml

So:-

1.5 x 106/ml2.0 x 106/mlis 0.75

A volume of 500 ml of cells
at 1.5 x 106/ml
is required

0.75 x 500 = 375 mlso take 375 ml of the
cell suspension

And add 125 ml of SM media

The experiment was set up as figure (left)

The edge of the slot in which the cells were added can be
seen at the bottom of the figure. Cells have crawled under the
agarose toward the folic acid slot beyond the top of this figure.

Distance from the edge of the slot to the first two cells
was measured the next morning.

Control cells had reached the other slot having
crawled toward the source all night. This makes a fair comparison
impossible yet the results still indicate that the inhibitors
effectively slowed chemotaxis. A comparison of the distance that
the cells took in the opposite direction shows that these inhibitors
also slowed the cell locomotory rate.